configure.in

dnl $Id$
dnl Copyright (c) 2001-2004, Roger Dingledine
dnl Copyright (c) 2004-2007, Roger Dingledine, Nick Mathewson
dnl See LICENSE for licensing information

AC_INIT
AM_INIT_AUTOMAKE(tor, 0.1.2.7-alpha-dev)
AM_CONFIG_HEADER(orconfig.h)

AC_CANONICAL_HOST

if test -f /etc/redhat-release; then
    CFLAGS="$CFLAGS -I/usr/kerberos/include"
fi

AC_ARG_ENABLE(debug,
 AC_HELP_STRING(--enable-debug, compile with debugging info),
[if test x$enableval = xyes; then
    CFLAGS="$CFLAGS -g"
fi])

AC_ARG_ENABLE(eventdns,
     AC_HELP_STRING(--enable-eventdns, enable asynchronous dns module),
     [case "${enableval}" in
        yes) eventdns=true ;;
        no)  eventdns=false ;;
        *) AC_MSG_ERROR(bad value for --enable-eventdns) ;;
      esac], [eventdns=true])
AM_CONDITIONAL(EVENTDNS, test x$eventdns = xtrue)
if test x$eventdns = xtrue; then
   AC_DEFINE([USE_EVENTDNS], 1, "Define to 1 if we'll be using eventdns.c")
fi

AC_ARG_ENABLE(transparent,
     AC_HELP_STRING(--disable-transparent, disable transparent proxy support),
     [case "${enableval}" in
        yes) transparent=true ;;
        no)  transparent=false ;;
        *) AC_MSG_ERROR(bad value for --enable-transparent) ;;
      esac], [transparent=true])

AC_ARG_ENABLE(threads,
     AC_HELP_STRING(--disable-threads, disable multi-threading support))

if test x$enable_threads = x; then
   case $host in
    *-*-netbsd* | *-*-openbsd* )
     # Don't try multithreading on netbsd -- there is no threadsafe DNS
     # lookup function there.
     if test x$eventdns != xtrue; then
        AC_MSG_NOTICE([You are running OpenBSD or NetBSD; I am assuming that
getaddrinfo is not threadsafe here, so I will disable threads.])
        enable_threads="no"
    fi ;;
    *-*-solaris* )
     # Don't try multithreading on solaris -- cpuworkers seem to lock.
     AC_MSG_NOTICE([You are running Solaris; Sometimes threading makes
cpu workers lock up here, so I will disable threads.])
     enable_threads="no";;
    *)
     enable_threads="yes";;
   esac
fi

if test $enable_threads = "yes"; then
  AC_DEFINE(ENABLE_THREADS, 1, [Defined if we will try to use multithreading])
fi

case $host in
   *-*-solaris* )
     AC_DEFINE(_REENTRANT, 1, [Define on some platforms to activate x_r() functions in time.h])
     ;;
esac

AC_ARG_ENABLE(gcc-warnings,
     AC_HELP_STRING(--enable-gcc-warnings, enable verbose warnings))

AC_PROG_CC
AC_PROG_MAKE_SET
AC_PROG_RANLIB

# The big search for OpenSSL
# copied from openssh's configure.ac
tryssldir=""
AC_ARG_WITH(ssl-dir,
        [  --with-ssl-dir=PATH     Specify path to OpenSSL installation ],
        [
                if test "x$withval" != "xno" ; then
                        tryssldir=$withval
                fi
        ]
)

trylibeventdir=""
AC_ARG_WITH(libevent-dir,
       [  --with-libevent-dir=PATH     Specify path to Libevent installation ],
       [
                if test "x$withval" != "xno" ; then
                        trylibeventdir=$withval
                fi
       ]
)

TORUSER=_tor
AC_ARG_WITH(tor-user,
        [  --with-tor-user=NAME    Specify username for tor daemon ],
        [
           TORUSER=$withval
        ]
)
AC_SUBST(TORUSER)

TORGROUP=_tor
AC_ARG_WITH(tor-group,
        [  --with-tor-group=NAME   Specify group name for tor daemon ],
        [
           TORGROUP=$withval
        ]
)
AC_SUBST(TORGROUP)


dnl If WIN32 is defined and non-zero, we are building for win32
AC_MSG_CHECKING([for win32])
AC_RUN_IFELSE([
int main(int c, char **v) {
#ifdef WIN32
#if WIN32
  return 0;
#else
  return 1;
#endif
#else
  return 2;
#endif
}],
bwin32=true; AC_MSG_RESULT([yes]),
bwin32=false; AC_MSG_RESULT([no]),
bwin32=cross; AC_MSG_RESULT([cross])
)

if test $bwin32 = cross; then
AC_MSG_CHECKING([for win32 (cross)])
AC_COMPILE_IFELSE([
#ifdef WIN32
int main(int c, char **v) {return 0;}
#else
#error
int main(int c, char **v) {return x(y);}
#endif
],
bwin32=true; AC_MSG_RESULT([yes]),
bwin32=false; AC_MSG_RESULT([no]))
fi

if test $bwin32 = true; then
AC_DEFINE(MS_WINDOWS, 1, [Define to 1 if we are building for Windows.])
fi

dnl Enable C99 when compiling with MIPSpro
AC_MSG_CHECKING([for MIPSpro compiler])
AC_TRY_COMPILE([], [
#if (defined(__sgi) && defined(_COMPILER_VERSION))
#error
  return x(y);
#endif
],
bmipspro=false; AC_MSG_RESULT([no]),
bmipspro=true; AC_MSG_RESULT([yes]))

if test $bmipspro = true; then
  CFLAGS="$CFLAGS -c99"
fi

AC_SEARCH_LIBS(socket, [socket])
AC_SEARCH_LIBS(gethostbyname, [nsl])
AC_SEARCH_LIBS(dlopen, [dl])
AC_SEARCH_LIBS(inet_aton, [resolv])

if test $enable_threads = "yes"; then
  AC_SEARCH_LIBS(pthread_create, [pthread])
  AC_SEARCH_LIBS(pthread_detach, [pthread])
fi

dnl -------------------------------------------------------------------
dnl Check for functions before libevent, since libevent-1.2 apparently
dnl exports strlcpy without defining it in a header.

AC_CHECK_FUNCS(gettimeofday ftime socketpair uname inet_aton strptime getrlimit strlcat strlcpy strtoull ftello getaddrinfo localtime_r gmtime_r memmem strtok_r)

if test $enable_threads = "yes"; then
  AC_CHECK_HEADERS(pthread.h)
  AC_CHECK_FUNCS(pthread_create)
fi

dnl ------------------------------------------------------
dnl Where do you live, libevent?  And how do we call you?

AC_CACHE_CHECK([for libevent directory], tor_cv_libevent_dir, [
  saved_LIBS="$LIBS"
  saved_LDFLAGS="$LDFLAGS"
  saved_CPPFLAGS="$CPPFLAGS"
  le_found=no
  for ledir in $trylibeventdir "" $prefix /usr/local /usr/pkg ; do
    LDFLAGS="$saved_LDFLAGS"

    if test $bwin32 = true; then
        LIBS="$saved_LIBS -levent -lws2_32"
    else
        LIBS="$saved_LIBS -levent"
    fi

    # Skip the directory if it isn't there.
    if test ! -z "$ledir" -a ! -d "$ledir" ; then
       continue;
    fi
    if test ! -z "$ledir" ; then
      if test -d "$ledir/lib" ; then
        LDFLAGS="-L$ledir/lib $LDFLAGS"
      else
        LDFLAGS="-L$ledir $LDFLAGS"
      fi
      if test -d "$ledir/include" ; then
        CPPFLAGS="-I$ledir/include $CPPFLAGS"
      else
        CPPFLAGS="-I$ledir $CPPFLAGS"
      fi
    fi
    # Can I compile and link it?
    AC_TRY_LINK([#include <sys/time.h>
#include <sys/types.h>
#include <event.h>], [ event_init(); ],
       [ libevent_linked=yes ], [ libevent_linked=no ])
    if test $libevent_linked = yes; then
       if test ! -z "$ledir" ; then
         tor_cv_libevent_dir=$ledir
       else
         tor_cv_libevent_dir="(system)"
       fi
       le_found=yes
       break
    fi
  done
  LIBS="$saved_LIBS"
  LDFLAGS="$saved_LDFLAGS"
  CPPFLAGS="$saved_CPPFLAGS"
  if test $le_found = no ; then
    AC_MSG_ERROR([Could not find a linkable libevent. You can specify an explicit path using --with-libevent-dir])
  fi
])

if test $bwin32 = true; then
LIBS="$LIBS -levent -lws2_32"
else
LIBS="$LIBS -levent"
fi
if test $tor_cv_libevent_dir != "(system)"; then
  if test -d "$tor_cv_libevent_dir/lib" ; then
    LDFLAGS="-L$tor_cv_libevent_dir/lib $LDFLAGS"
    le_libdir="$tor_cv_libevent_dir/lib"
  else
    LDFLAGS="-L$tor_cv_libevent_dir $LDFLAGS"
    le_libdir="$tor_cv_libevent_dir"
  fi
  if test -d "$tor_cv_libevent_dir/include" ; then
    CPPFLAGS="-I$tor_cv_libevent_dir/include $CPPFLAGS"
  else
    CPPFLAGS="-I$tor_cv_libevent_dir $CPPFLAGS"
  fi
fi

if test -z "$CROSS_COMPILE"; then
AC_CACHE_CHECK([whether we need extra options to link libevent],
               tor_cv_libevent_linker_option, [
    saved_LDFLAGS="$LDFLAGS"
    le_runs=no
    linked_with=nothing
    for le_extra in "" "-Wl,-R$le_libdir" "-R$le_libdir" "-Wl,-rpath,$le_libdir" ; do
      LDFLAGS="$le_extra $saved_LDFLAGS"
      AC_TRY_RUN([void *event_init(void);
                int main(int c, char **v) {
                   event_init(); return 0;
                }],
                libevent_runs=yes, libevent_runs=no, libevent_runs=cross)
      if test $libevent_runs != no ; then
        if test -z "$le_extra" ; then
          tor_cv_libevent_linker_option='(none)'
        else
          tor_cv_libevent_linker_option=$le_extra
        fi
        le_runs=yes
        break
      fi
    done
    if test $le_runs = no ; then
      AC_MSG_ERROR([Found linkable libevent in $tor_cv_libevent_dir, but it doesn't run, even with -R.  Maybe specify another using --with-libevent-dir?])
    fi
    LDFLAGS="$saved_LDFLAGS"
])

if test $tor_cv_libevent_linker_option != '(none)' ; then
   LDFLAGS="$tor_cv_libevent_linker_option $LDFLAGS"
fi
fi

dnl Now check for particular libevent functions.
AC_CHECK_FUNCS(event_get_version event_get_method event_set_log_callback)

dnl ------------------------------------------------------
dnl Where do you live, openssl?  And how do we call you?

AC_CACHE_CHECK([for OpenSSL directory], tor_cv_openssl_dir, [
  saved_LIBS="$LIBS"
  saved_LDFLAGS="$LDFLAGS"
  saved_CPPFLAGS="$CPPFLAGS"
  ssl_found=no
  for ssldir in $tryssldir "" $prefix /usr/local/openssl /usr/lib/openssl /usr/local/ssl /usr/lib/ssl /usr/local /usr/athena /usr/pkg /opt /opt/openssl ; do
    LDFLAGS="$saved_LDFLAGS"

    if test $bwin32 = true; then
      LIBS="$saved_LIBS -lssl -lcrypto -lws2_32 -lgdi32"
    else
      LIBS="$saved_LIBS -lssl -lcrypto"
    fi

    # Skip the directory if it isn't there.
    if test ! -z "$ssldir" -a ! -d "$ssldir" ; then
       continue;
    fi
    if test ! -z "$ssldir" ; then
      if test -d "$ssldir/lib" ; then
        LDFLAGS="-L$ssldir/lib $LDFLAGS"
      else
        LDFLAGS="-L$ssldir $LDFLAGS"
      fi
      if test -d "$ssldir/include" ; then
        CPPFLAGS="-I$ssldir/include $CPPFLAGS"
      else
        CPPFLAGS="-I$ssldir $CPPFLAGS"
      fi
    fi
    # Can I link it?
    AC_TRY_LINK([#include <openssl/rand.h>],
       [ RAND_add((void*)0,0,0); ],
       [ openssl_linked=yes ], [ openssl_linked=no ])
    if test $openssl_linked = yes; then
       if test ! -z "$ssldir" ; then
         tor_cv_openssl_dir=$ssldir
       else
         tor_cv_openssl_dir="(system)"
       fi
       ssl_found=yes
       break
    fi
  done
  LIBS="$saved_LIBS"
  LDFLAGS="$saved_LDFLAGS"
  CPPFLAGS="$saved_CPPFLAGS"
  if test $ssl_found = no ; then
    AC_MSG_ERROR([Could not find a linkable OpenSSL. You can specify an explicit path using --with-ssl-dir])
  fi
])

if test $bwin32 = true; then
LIBS="$LIBS -lssl -lcrypto -lws2_32 -lgdi32"
else
LIBS="$LIBS -lssl -lcrypto"
fi

if test "$tor_cv_openssl_dir" != "(system)"; then
  if test -d "$tor_cv_openssl_dir/lib" ; then
    LDFLAGS="-L$tor_cv_openssl_dir/lib $LDFLAGS"
    ssl_libdir="$tor_cv_openssl_dir/lib"
  else
    LDFLAGS="-L$tor_cv_openssl_dir $LDFLAGS"
    ssl_libdir="$tor_cv_openssl_dir"
  fi
  if test -d "$tor_cv_openssl_dir/include" ; then
    CPPFLAGS="-I$tor_cv_openssl_dir/include $CPPFLAGS"
  else
    CPPFLAGS="-I$tor_cv_openssl_dir $CPPFLAGS"
  fi
fi

if test -z "$CROSS_COMPILE"
then
AC_CACHE_CHECK([whether we need extra options to link OpenSSL],
               tor_cv_openssl_linker_option, [
    saved_LDFLAGS="$LDFLAGS"
    ssl_runs=no
    linked_with=nothing
    for ssl_extra in "" "-Wl,-R$ssl_libdir" "-R$ssl_libdir" ; do
      LDFLAGS="$ssl_extra $saved_LDFLAGS"
      AC_TRY_RUN([
#include <string.h>
#include <openssl/rand.h>
int main(void)
{
        char a[2048];
        memset(a, 0, sizeof(a));
        RAND_add(a, sizeof(a), sizeof(a));
        return(RAND_status() <= 0);
}
                        ],
                openssl_runs=yes, openssl_runs=no, openssl_runs=cross)
      if test $openssl_runs != no ; then
        if test "$linked_with" = nothing; then
           linked_with="$ssl_extra"
        fi
        AC_TRY_RUN([
#include <openssl/opensslv.h>
#include <openssl/crypto.h>
int main(void) {
return (OPENSSL_VERSION_NUMBER == SSLeay()) == 0;
}],
        right_version=yes, right_version=no)
        if test "$right_version" = yes; then
          if test -z "$ssl_extra" ; then
            tor_cv_openssl_linker_option='(none)'
          else
            tor_cv_openssl_linker_option=$ssl_extra
          fi
          ssl_runs=yes
          break
        fi
     fi
    done
    if test $ssl_runs = no ; then
      if test "$linked_with" = 'nothing' ; then
        AC_MSG_ERROR([Found linkable OpenSSL in $tor_cv_openssl_dir, but it doesn't run, even with -R.  Maybe specify another using --with-ssl-dir?])
      else
        if test -z "$linked_with" ; then
            tor_cv_openssl_linker_option='(none)'
        else
            tor_cv_openssl_linker_option=$linked_with
        fi
        AC_MSG_WARN([I managed to make OpenSSL link and run, but I couldn't make it link against the same version I found header files for.])
      fi
    fi
    LDFLAGS="$saved_LDFLAGS"
])

if test "$tor_cv_openssl_linker_option" != '(none)' ; then
   LDFLAGS="$tor_cv_openssl_linker_option $LDFLAGS"
fi
fi

dnl Make sure to enable support for large off_t if avalable.

AC_SYS_LARGEFILE

dnl The warning message here is no longer strictly accurate.

AC_CHECK_HEADERS(unistd.h string.h signal.h ctype.h sys/stat.h sys/types.h fcntl.h sys/fcntl.h sys/time.h errno.h assert.h time.h, , AC_MSG_WARN(some headers were not found, compilation may fail))

AC_CHECK_HEADERS(netdb.h sys/ioctl.h sys/socket.h arpa/inet.h netinet/in.h pwd.h grp.h)

AC_CHECK_HEADERS(event.h, , AC_MSG_ERROR(Libevent header (event.h) not found. Tor requires libevent to build.),
[#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#else
  struct timeval {
    long tv_sec;
    long tv_usec;
 };
#endif])

AC_CHECK_HEADERS(zlib.h, , AC_MSG_ERROR(Zlib header (zlib.h) not found. Tor requires zlib to build. You may need to install a zlib development package.))

dnl These headers are not essential

AC_CHECK_HEADERS(stdint.h sys/types.h inttypes.h sys/param.h sys/wait.h limits.h sys/limits.h netinet/in.h arpa/inet.h machine/limits.h syslog.h sys/time.h sys/resource.h inttypes.h utime.h sys/utime.h sys/mman.h netintet/in.h netinet/in6.h)

AC_CHECK_HEADERS(net/if.h, [net_if_found=1], [net_if_found=0],
[#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif])
AC_CHECK_HEADERS(net/pfvar.h, [net_pfvar_found=1], [net_pfvar_found=0],
[#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif])
AC_CHECK_HEADERS(linux/netfilter_ipv4.h,
        [linux_netfilter_ipv4=1], [linux_netfilter_ipv4=0],
[#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif])

if test x$transparent = xtrue ; then
   transparent_ok=0
   if test x$net_if_found = x1 -a x$net_pfvar_found = x1 ; then
     transparent_ok=1
   fi
   if test x$linux_netfilter_ipv4 = x1 ; then
     transparent_ok=1
   fi
   if test x$transparent_ok = x1 ; then
     AC_DEFINE(USE_TRANSPARENT, 1, "Define to enable transparent proxy support")
     case $host in
       *-*-openbsd*)
         AC_DEFINE(OPENBSD, 1, "Define to handle pf on OpenBSD properly") ;;
     esac
   else
     AC_MSG_NOTICE([Transparent proxy support enabled, but missing headers.])
   fi
fi

AC_FUNC_FSEEKO

AC_CHECK_MEMBERS([struct timeval.tv_sec], , ,
[#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif])

dnl In case we aren't given a working stdint.h, we'll need to grow our own.
dnl Watch out.

AC_CHECK_SIZEOF(int8_t)
AC_CHECK_SIZEOF(int16_t)
AC_CHECK_SIZEOF(int32_t)
AC_CHECK_SIZEOF(int64_t)
AC_CHECK_SIZEOF(uint8_t)
AC_CHECK_SIZEOF(uint16_t)
AC_CHECK_SIZEOF(uint32_t)
AC_CHECK_SIZEOF(uint64_t)
AC_CHECK_SIZEOF(intptr_t)
AC_CHECK_SIZEOF(uintptr_t)

dnl AC_CHECK_TYPES([int8_t, int16_t, int32_t, int64_t, uint8_t, uint16_t, uint32_t, uint64_t, intptr_t, uintptr_t])

AC_CHECK_SIZEOF(char)
AC_CHECK_SIZEOF(short)
AC_CHECK_SIZEOF(int)
AC_CHECK_SIZEOF(long)
AC_CHECK_SIZEOF(long long)
AC_CHECK_SIZEOF(__int64)
AC_CHECK_SIZEOF(void *)
AC_CHECK_SIZEOF(time_t)
AC_CHECK_SIZEOF(size_t)

AC_CHECK_TYPES([uint, u_char])

AC_CHECK_TYPES([struct in6_addr, struct sockaddr_storage], , ,
[#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_NETINET_IN6_H
#include <netinet/in6.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif])

if test -z "$CROSS_COMPILE"; then
AC_CACHE_CHECK([whether time_t is signed], tor_cv_time_t_signed, [
AC_TRY_RUN([
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#ifdef HAVE_TIME_H
#include <time.h>
#endif
int main(int c, char**v) { if (((time_t)-1)<0) return 1; else return 0; }],
  tor_cv_time_t_signed=no, tor_cv_time_t_signed=yes)
])
else
  # Cross-compiling; let's hope the target platform isn't loony.
  AC_MSG_NOTICE([Cross compiling: assuming that time_t is signed.])
  tor_cv_time_t_signed=yes
fi

if test $tor_cv_time_t_signed = yes; then
  AC_DEFINE([TIME_T_IS_SIGNED], 1,
            [Define to 1 iff time_t is signed])
fi

AC_CHECK_SIZEOF(socklen_t, , [AC_INCLUDES_DEFAULT()
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
])

# We want to make sure that we _don't_ have a cell_t defined, like IRIX does.

AC_CHECK_SIZEOF(cell_t)

# Now make sure that NULL can be represented as zero bytes.
if test -z "$CROSS_COMPILE"; then
AC_CACHE_CHECK([whether memset(0) sets pointers to NULL], tor_cv_null_is_zero,
[AC_RUN_IFELSE([AC_LANG_SOURCE(
[[#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#ifdef HAVE_STDDEF_H
#include <stddef.h>
#endif
int main () { char *p1,*p2; p1=NULL; memset(&p2,0,sizeof(p2));
return memcmp(&p1,&p2,sizeof(char*))?1:0; }]])],
       [tor_cv_null_is_zero=yes],
       [tor_cv_null_is_zero=no],
       [tor_cv_null_is_zero=cross])])

else
  # Cross-compiling; let's hope that the target isn't raving mad.
  AC_MSG_NOTICE([Cross-compiling: we'll assume that NULL is represented as a sequence of 0-valued bytes.])
  tor_cv_null_is_zero=yes
fi

if test $tor_cv_null_is_zero = yes; then
  AC_DEFINE([NULL_REP_IS_ZERO_BYTES], 1,
            [Define to 1 iff memset(0) sets pointers to NULL])
fi

# And what happens when we malloc zero?

if test -z "$CROSS_COMPILE"; then
AC_CACHE_CHECK([whether we can malloc(0) safely.], tor_cv_malloc_zero_works,
[AC_RUN_IFELSE([AC_LANG_SOURCE(
[[#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#ifdef HAVE_STDDEF_H
#include <stddef.h>
#endif
int main () { return malloc(0)?0:1; }]])],
       [tor_cv_malloc_zero_works=yes],
       [tor_cv_malloc_zero_works=no],
       [tor_cv_malloc_zero_works=cross])])

else
  # Cross-compiling; let's hope that the target isn't raving mad.
  AC_MSG_NOTICE([Cross-compiling: we'll assume that we need to check malloc() arguments for 0.])
  tor_cv_malloc_zero_works=no
fi

if test $tor_cv_malloc_zero_works = yes; then
  AC_DEFINE([MALLOC_ZERO_WORKS], 1,
            [Define to 1 iff malloc(0) returns a pointer])
fi

# whether we seem to be in a 2s-complement world.
if test -z "$CROSS_COMPILE"; then
AC_CACHE_CHECK([whether we are using 2s-complement arithmetic], tor_cv_twos_complement,
[AC_RUN_IFELSE([AC_LANG_SOURCE(
[[int main () { int problem = ((-99) != (~99)+1);
return problem ? 1 : 0; }]])],
       [tor_cv_twos_complement=yes],
       [tor_cv_twos_complement=no],
       [tor_cv_twos_complement=cross])])

else
  # Cross-compiling; let's hope that the target isn't raving mad.
  AC_MSG_NOTICE([Cross-compiling: we'll assume that negative integers are represented with two's complement.])
  tor_cv_twos_complement=yes
fi

if test $tor_cv_twos_complement = yes; then
  AC_DEFINE([USING_TWOS_COMPLEMENT], 1,
            [Define to 1 iff we represent negative integers with two's complement])
fi

# Whether we should use the dmalloc memory allocation debugging library.
AC_MSG_CHECKING(whether to use dmalloc (debug memory allocation library))
AC_ARG_WITH(dmalloc,
[  --with-dmalloc          Use debug memory allocation library. ],
[if [[ "$withval" = "yes" ]]; then
  dmalloc=1
  AC_MSG_RESULT(yes)
else
  dmalloc=1
  AC_MSG_RESULT(no)
fi], [ dmalloc=0; AC_MSG_RESULT(no) ]
)

if [[ $dmalloc -eq 1 ]]; then
  AC_CHECK_HEADERS(dmalloc.h, , AC_MSG_ERROR(dmalloc header file not found. Do you have the development files for dmalloc installed?))
  AC_SEARCH_LIBS(dmalloc_malloc, [dmallocth dmalloc], , AC_MSG_ERROR(Libdmalloc library not found. If you enable it you better have it installed.))
  AC_DEFINE(USE_DMALLOC, 1, [Debug memory allocation library])
  AC_DEFINE(DMALLOC_FUNC_CHECK, 1, [Enable dmalloc's malloc function check])
fi

# Allow user to specify an alternate syslog facility
AC_ARG_WITH(syslog-facility,
[  --with-syslog-facility=LOG syslog facility to use (default=LOG_DAEMON)],
syslog_facility="$withval", syslog_facility="LOG_DAEMON")
AC_DEFINE_UNQUOTED(LOGFACILITY,$syslog_facility,[name of the syslog facility])
AC_SUBST(LOGFACILITY)

# Check for gethostbyname_r in all its glorious incompatible versions.
#   (This logic is based on that in Python's configure.in)
AH_TEMPLATE(HAVE_GETHOSTBYNAME_R,
  [Define this if you have any gethostbyname_r()])

AC_CHECK_FUNC(gethostbyname_r, [
  AC_MSG_CHECKING([how many arguments gethostbyname_r() wants])
  OLD_CFLAGS=$CFLAGS
  CFLAGS="$CFLAGS $MY_CPPFLAGS $MY_THREAD_CPPFLAGS $MY_CFLAGS"
  AC_TRY_COMPILE([
#include <netdb.h>
  ], [
    char *cp1, *cp2;
    struct hostent *h1, *h2;
    int i1, i2;
    (void)gethostbyname_r(cp1,h1,cp2,i1,&h2,&i2);
  ], [
    AC_DEFINE(HAVE_GETHOSTBYNAME_R)
    AC_DEFINE(HAVE_GETHOSTBYNAME_R_6_ARG, 1,
     [Define this if gethostbyname_r takes 6 arguments])
    AC_MSG_RESULT(6)
  ], [
    AC_TRY_COMPILE([
#include <netdb.h>
    ], [
      char *cp1, *cp2;
      struct hostent *h1;
      int i1, i2;
      (void)gethostbyname_r(cp1,h1,cp2,i1,&i2);
    ], [
      AC_DEFINE(HAVE_GETHOSTBYNAME_R)
      AC_DEFINE(HAVE_GETHOSTBYNAME_R_5_ARG, 1,
        [Define this if gethostbyname_r takes 5 arguments])
      AC_MSG_RESULT(5)
   ], [
      AC_TRY_COMPILE([
#include <netdb.h>
     ], [
       char *cp1;
       struct hostent *h1;
       struct hostent_data hd;
       (void) gethostbyname_r(cp1,h1,&hd);
     ], [
       AC_DEFINE(HAVE_GETHOSTBYNAME_R)
       AC_DEFINE(HAVE_GETHOSTBYNAME_R_3_ARG, 1,
         [Define this if gethostbyname_r takes 3 arguments])
       AC_MSG_RESULT(3)
     ], [
       AC_MSG_RESULT(0)
     ])
  ])
 ])
 CFLAGS=$OLD_CFLAGS
])

AC_CACHE_CHECK([whether the C compiler supports __func__],
  tor_cv_have_func_macro,
  AC_COMPILE_IFELSE([
#include <stdio.h>
int main(int c, char **v) { puts(__func__); }],
  tor_cv_have_func_macro=yes,
  tor_cv_have_func_macro=no))

AC_CACHE_CHECK([whether the C compiler supports __FUNC__],
  tor_cv_have_FUNC_macro,
  AC_COMPILE_IFELSE([
#include <stdio.h>
int main(int c, char **v) { puts(__FUNC__); }],
  tor_cv_have_FUNC_macro=yes,
  tor_cv_have_FUNC_macro=no))

AC_CACHE_CHECK([whether the C compiler supports __FUNCTION__],
  tor_cv_have_FUNCTION_macro,
  AC_COMPILE_IFELSE([
#include <stdio.h>
int main(int c, char **v) { puts(__FUNCTION__); }],
  tor_cv_have_FUNCTION_macro=yes,
  tor_cv_have_FUNCTION_macro=no))

if test $tor_cv_have_func_macro = 'yes'; then
  AC_DEFINE(HAVE_MACRO__func__, 1, [Defined if the compiler supports __func__])
fi

if test $tor_cv_have_FUNC_macro = 'yes'; then
  AC_DEFINE(HAVE_MACRO__FUNC__, 1, [Defined if the compiler supports __FUNC__])
fi

if test $tor_cv_have_FUNCTION_macro = 'yes'; then
  AC_DEFINE(HAVE_MACRO__FUNCTION__, 1,
           [Defined if the compiler supports __FUNCTION__])
fi

# $prefix stores the value of the --prefix command line option, or
# NONE if the option wasn't set.  In the case that it wasn't set, make
# it be the default, so that we can use it to expand directories now.
if test "x$prefix" = "xNONE"; then
  prefix=$ac_default_prefix
fi

# and similarly for $exec_prefix
if test "x$exec_prefix" = "xNONE"; then
  exec_prefix=$prefix
fi

if test "x$CONFDIR" = "x"; then
  CONFDIR=`eval echo $sysconfdir/tor`
fi
AC_SUBST(CONFDIR)
AH_TEMPLATE([CONFDIR],[tor's configuration directory])
AC_DEFINE_UNQUOTED(CONFDIR,"$CONFDIR")

BINDIR=`eval echo $bindir`
AC_SUBST(BINDIR)

LOCALSTATEDIR=`eval echo $localstatedir`
AC_SUBST(LOCALSTATEDIR)
AH_TEMPLATE([LOCALSTATEDIR], [Default location to store state files.])
AC_DEFINE_UNQUOTED(LOCALSTATEDIR,"$LOCALSTATEDIR")

# Set CFLAGS _after_ all the above checks, since our warnings are stricter
# than autoconf's macros like.
if test $ac_cv_c_compiler_gnu = yes; then
  CFLAGS="$CFLAGS -Wall -g -O2"
else
  CFLAGS="$CFLAGS -g -O"
  enable_gcc_warnings=no
fi

# Add some more warnings which we use in the cvs version but not in the
# released versions.  (Some relevant gcc versions can't handle these.)
if test x$enable_gcc_warnings = xyes; then

  AC_TRY_COMPILE([], [
#if !defined(__GNUC__) || (__GNUC__ < 4)
#error
#endif], have_gcc4=yes, have_gcc4=no)

  CFLAGS="$CFLAGS -W -Wfloat-equal -Wundef -Wpointer-arith -Wstrict-prototypes -Wmissing-prototypes -Wwrite-strings -Wredundant-decls -Wchar-subscripts -Wcomment -Wformat=2 -Wwrite-strings -Waggregate-return -Wmissing-declarations -Wredundant-decls -Wnested-externs -Wbad-function-cast -Wswitch-enum -Werror"

  if test x$have_gcc4 = xyes ; then 
    # These warnings break gcc 3.3.5 and work on gcc 4.0.2
    CFLAGS="$CFLAGS -Winit-self -Wmissing-field-initializers -Wdeclaration-after-statement -Wold-style-definition"
  fi

##This will break the world on some 64-bit architectures
# CFLAGS="$CFLAGS -Winline"

fi

AC_OUTPUT(Makefile tor.spec contrib/tor.sh contrib/torctl contrib/torify contrib/tor.logrotate contrib/Makefile contrib/osx/Makefile contrib/osx/TorBundleDesc.plist contrib/osx/TorBundleInfo.plist contrib/osx/TorDesc.plist contrib/osx/TorInfo.plist contrib/osx/TorStartupDesc.plist src/config/torrc.sample doc/tor.1 src/Makefile doc/Makefile doc/design-paper/Makefile doc/spec/Makefile src/config/Makefile src/common/Makefile src/or/Makefile src/win32/Makefile src/tools/Makefile contrib/suse/Makefile contrib/suse/tor.sh)

if test -x /usr/bin/perl && test -x ./contrib/updateVersions.pl ; then
  ./contrib/updateVersions.pl
fi